I've been playing around in Sketchup, lately. The possibilities for gaming are huge. I've been taking the inside covers of old modules and turning them into 3d maps. I'm barely learning the functions, but it's almost as easy as tracing around different shapes and pulling them up to whatever height you need. Buildings, cave walls, contour lines, this prog does it all.
Working on a huge drow cave right now, It's taking some time.